Coding Standards: Add missing global variable docblock in /wp-admin/network/upgrade.php.

Props upadalavipul.



git-svn-id: https://develop.svn.wordpress.org/trunk@60095 602fd350-edb4-49c9-b593-d223f7449a82

Author: audrasjb

src/wp-admin/network/upgrade.php

@@ -135,6 +135,9 @@ function nextpage() {
 		break;
 	case 'show':
 	default:
+		/**
+		 * @global int $wp_db_version WordPress database version.
+		 */
 		if ( (int) get_site_option( 'wpmu_upgrade_site' ) !== $GLOBALS['wp_db_version'] ) :
 			?>
 		<h2><?php _e( 'Database Update Required' ); ?></h2>